Purpose: To further understand more of the advanced model editing tools and techniques.

Objective: Explain the Tweak Tool, Proportional Modeling, Symmetry Mode and Duplicating components of a model.

Proportional Modeling

When you manipulate points, edges, and polygons, you can use proportional modeling. When this option is on, neighboring components are affected as well, with a falloff that depends on a configurable distance. Components that will be affected are highlighted in the 3D views.

You can enable Proportional Modeling from the MCP by clicking the Prop button on the Transform panel or choose Modify > Component > Proportional.

  • With the tweak tool still selected, left click to activate and you can see how the circle follows the profile of the object. By pressing (R), or right clicking (Prop) from the MCP, you can access the distance limit of the radius. Hold R, scroll left to right, and you can change the distance limit of the proportional tool.

Symmetry Mode

Symmetrical manipulation lets you manipulate points and other components and maintain the symmetry of an object. Any manipulations performed on components on one side are mirrored to the corresponding components on the other side. Components that lie directly on the plane of symmetry are "locked down"; they can be translated or moved only along the plane of symmetry itself.

Tools that Work with Sym Mode

  • Scale tool on points, edges, and polygons (X)
  • Rotate tool on points, edges, and polygons (C)
  • Translate tool on points, edges, and polygons (V)
  • Tweak Component tool on points, edges, and polygons (M)
  • And a few other tools we will not be covering at this time

Using the Tweak Component Tool we can symmetrically tweak our object. Now if we ever need to change the size of the Tool, again hold R for radius and drag left or right. To change the plane of Symmetry manipulation, right click the (Sym) button and select the appropriate axis to model symmetrically from.

The Symmetry Plane options are

YZ = Front Orthographic Viewport
XZ = Right Orthographic Viewport (top and bottom of the object)
XY = Right Orthographic Viewport

Note: The Proportional Manipulation and Symmetry Mode tools can be used without the tweak tool, however they are most effective with it.

Exercise 1

Spend at least 15 minutes working with the proportional and symmetry tools to become familiar with them. Create various Polygon Mesh primitive objects and practice using these tools. All the while remember to utilize all of the Hotkeys we have learned, while navigating in the Camera Viewport to view changes we make to our objects from different angles.

Exercise 2

Create a simplified head

  • Create a new Scene > Polygon Mesh > Sphere and enabled shading in the Camera Viewport.
  • Modify U/V Subdivision to 48 and increase the Radius to 6 and close the property window.
  • Enable Prop and Sym modes and activate the Tweak Tool Mode (M).
  • Enter Full screen mode in the Camera Viewport.

Rather than list every step by step; practice what you have learned to create basic facial features.
Utilize the SRT Axis constraints to control which direction you modify in.

TIP: Remember to use Distance Limit tool (hold R and drag) to affect larger or smaller areas of your modifications.
TIP: Be sure to switch between edges, points and polygons.

We do not need to create a perfect face here. We are looking to create a simplified face. Spend around 20 minutes fine tuning the facial feature of the face.

Duplicating Polygons (Faces)

Next we will cover the very common practice of duplicating a polygon to modify the shape of our model.

  • Get > Primitive > Polygon Mesh > Cube
  • Press (U) to activate Raycast Polygon select
  • Select any face of the cube and press CTRL D to duplicate

Note: at first it will appear as nothing happens, however, once you translate the newly created polygon away from the position it was duplicated from, you will see the result.

  • Press V to translate the newly created polygon.

We have effectively converted a square comprised of 6 faces into a rectangle comprised of 10 faces!

Believe it or not but this is one of the most common shortcuts/techniques to develop a model (depending on what you’re doing). Whether you are modeling an object for an Animation scene, or for a game, it is often required to keep the object as “one” object, and not have to merge multiple separate objects together. As you being to work with more complex shapes, simple techniques like this can be a life saver.

Duplicating Points

Another way to quickly split up a model mesh is by duplicating a point on the model. Select any point and press CTRL D to duplicate.

Observe that it created 4 points (in this model example). This method may not be ideal in some instances, or on complex model meshes, as it will approximate what it thinks you may want based on the existing model shape.

Experiment with this for a bit to get a feel for how it works.

Duplicating Edges

We can also duplicate edges in much the same way as points are duplicated. The result will always be an approximation of what the program thinks you are trying to do. If we select an edge on the outside edge of our rectangle, and press CTRL D will occur:

Again, this type of duplication may not be desired in many scenarios – but in working with primitive objects especially, you may indeed find it to be a quick way to break up your primitive object into more polygons allowing you to create an object you have in mind.

As with the points, spend some time experimenting with duplicating edges. Overall, spend at least 15 minutes experimenting with duplicating polygons, edges and points as described above.

Add Edge Tool

And finally, using the Add Edge Tool we can split up any polygon face (or entire model) precisely to our specifications. Remember, by adding more edges to a model, we are in turn adding points and polygons to the model (edges start and end with points and are surrounded by polygonal faces, i.e. the model mesh).

With our rectangle still selected, access the Add Edge Tool from the Model Menu on the top shelf as follows:

  • Model > Modify > Poly. Mesh > Add Edge Tool – hotkey ( \ )
  • LMB click an edge on the top surface of the rectangle
  • There will now be a line connecting from your mouse cursor to the newly created point you just made by clicking on the edge.
  • To complete your new edge LMB click on a new edge across from the first point.
  • At this point you can either hit escape to exit the Add Edge Tool if you only wished to add this one new edge across the top surface. However if you desire you can elect to keep this tool active and continue clicking edges around the entire rectangle, thus creating another partition of our original square and increasing the number of polygons and points our object is created from.
  • To connect your new edge to an existing point (like the first point you created with this tool), simply hover you mouse the point and it will hover RED, indicating that the point is ready to connect to your previous point. via a new edge.

Lesson Summary

We covered a lot of ground in this lesson:

  • Proportional Modeling
  • Symmetry Mode
  • Duplicating Polygons, Edges and Points
  • and finally the Add Edge Tool

These are very powerful tools that between them can handle nearly any modeling requirement your design may have.

Overall, the Add Edge Tool will be used most often. It affords the most flexibility and control in allowing you to break up a model and its polygons, granting you the ability to shape your creation with the most amount of control (in the form of edges you add deliberately).

It is recommended that the students spend at least 30 minutes reviewing and experimenting with all of these tools. As an activity, discuss the simple, yet everyday objects that can be created with these tools – and do so as time permits.

  • Feel free to save your work in the Scenes Directory under Haus of Mapping Curriculum Project Path.

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